Replace assertion errors with specific exceptions

[rolnico]

Please check if the PR fulfills these requirements

• The commit message follows our guidelines
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

Does this PR already have an issue describing the problem?
No

What kind of change does this PR introduce?
Feature

Does this PR introduce a new Powsybl Action implying to be implemented in simulators or pypowsybl?

• Yes, the corresponding issue is here
• No

What is the current behavior?
Many AssertionErrors are thrown in the code

What is the new behavior (if this is a feature change)?
AssertionErrors have been replaced by specific exceptions

Does this PR introduce a breaking change or deprecate an API?

• Yes
• No

If yes, please check if the following requirements are fulfilled

• The Breaking Change or Deprecated label has been added
• The migration steps are described in the following section

What changes might users need to make in their application due to this PR? (migration steps)

Other information:

[sonarqubecloud]

Quality Gate failed

Failed conditions
1 Security Hotspot
63.2% Coverage on New Code (required ≥ 80%)

See analysis details on SonarQube Cloud